1. 
   
   Definition of BLUNT TRAUMA. : a usually serious injury caused by ablunt object or collision with a blunt surface (as in a vehicle accident or fall from a building) <the patient died of blunt trauma to the head>-called also blunt force trauma.
   In the case of slingshots your killing will the force/ impact more than penetration with the projectile with bleeding.
   

 

Impact- that is the rate of change of momentum?

What I don't understand is is why do we slingsooters talk about energy!!!???

 

When someone smacks your head with a baseball bat, that's blunt trauma.

Regards,

Mike

 

Jack trevalty, I think the energy at least gives us numbers and it's something that can be calculated. You can get clean kills with a 5/8 marble at 4 foot pounds of energy with good head shots. Blunt force trauma is very deadly for game that's why I prefer at least .45 cal lead for hunting

 

Jack trevalty, I think the energy at least gives us numbers and it's something that can be calculated. You can get clean kills with a 5/8 marble at 4 foot pounds of energy with good head shots. Blunt force trauma is very deadly for game that's why I prefer at least .45 cal lead for hunting

 

Foot pounds of energy is good for figuring out how much power you are achieving because its a standardized scale. 8 foot pounds is 8 foot pounds. Speed is relative to what ammo you are using where as energy is not. Now ammo can deliver a different energy depending on expansion and penetration but FPE is a good baseline for hunting effectiveness.

 

So there's a little question for you.

what will you choose?

A 1.5grams lead ball moving at 400fps or a 5g marble moving at 160fps?

I bet you went to feed that in a calculator did you!? Lol

 

1.5 grams that's about the size of a bb? My nephews play air soft and their guns shoot 400 fps nobody complains about getting shot. A marble can be used to hunt but id want about 200 fps with a headshot. With those 2 options your better off hunting a pop can

 

That is a 1\4 inch lead ball! I'm pretty sure that will bloody hurt if that hit someone at 400fps.

 

1.5 grams that's about the size of a bb? My nephews play air soft and their guns shoot 400 fps nobody complains about getting shot. A marble can be used to hunt but id want about 200 fps with a headshot. With those 2 options your better off hunting a pop can

Your probably thinking of .15 grams. A normal airsoft bb is .12 grams

 

I just got home and weighd a bb. Yup only .4 grams. The closes thing I could find to 1.5 grams is a piece of sweet tart candy at 1.1 grams. My hands may be a bit calloused but I couldnt even feel that in my hand i couldnt imagine hunting with it. you probably be able to at least stun a spruce chicken long enough with the marble on a head shot at 160 fps and collect and I'm assuming it's a hypothetical question. 7.5 gram steel at 160 fps is enough to hunt with though

 

Yeah, most people set the Tonearm of their record player at 1.5 g. The heavier weight, although travelling slower 160 fps is the more forceful.

Nicholson said:

I just got home and weighd a bb. Yup only .4 grams. The closes thing I could find to 1.5 grams is a piece of sweet tart candy at 1.1 grams. My hands may be a bit calloused but I couldnt even feel that in my hand i couldnt imagine hunting with it. you probably be able to at least stun a spruce chicken long enough with the marble on a head shot at 160 fps and collect and I'm assuming it's a hypothetical question. 7.5 gram steel at 160 fps is enough to hunt with though

DogBox added:

With 1500 posts I woulda thought Jacktrevally would have come across that by now...? or is he teasing us!

 

I have come across a few discussion on these over the years.

Actually a 1.5gram ammo moving at 400fps has about twice the energy of a 5grams ammo moving at 160fps.

So what to believe now???

 

Yeah, most people set the Tonearm of their record player at 1.5 g. The heavier weight, although travelling slower 160 fps is the more forceful.

The smaller lead will have around 8 fpe compared to the 5 gram ammo's 4 fpe.

 

that's pretty minimal but possible. better get the soup can out and test them should get the marble up to 200fps though which is easy to do

 

Unlike foot lbs of energy, M x V squared/450250 Momentum is a function of pure mass x velocity.

A 22lr has about 128fpe but 48,000 units of momentum

A 120gr lead ball at 200fps has only 10.6fpe but has 24,000 units of momentum ... half of what a 22lr does

The blunt trauma of a slingshot is pretty impressive

If you use the Taylor Knock Out formula the sling shot is even more impressive, with a slingshot it is about the smash

22lr ......... 40gr x 1200v x .224dia = 10752/7000 = 1.538 Taylor

Sling Shot ......... 129gr x 200v x .385dia = 9240/7000 = 1.32 Taylor

Taylor factor was used for an non scientific unit to measure the effect of bullets on game, showing that big heavy projectiles are very effective on game animals. Taylor devised this formula after hunting and seeing thousands of animals being shot by a variety of calibers and seeing the effects of heavy slower moving projectiles on game. It pretty much has stood the test of time in real life situations.

wll

 

How do you get 1.5g to move at 400fps...? by something else other than a 'slingshot...!

DB

 

I'd an overview of the Taylor knock out and the Thornily formula which has an index chart.

Quite interesting!

The product of momentum and energy gives another interesting value called the kinetic pulse.

 

slingshot hunting is different from rifle hunting. In Rifle hunting the bullet must penetrate and it counts on blood loss to kill. You can factor in kinetic pulse, hydrostatic shock and whatever else rifle hunting science involves. Slingshots use blunt force trauma to kill for the most part and a heavier bullet is more effective givin enough velocity in this regard. As for kinetic pulse, the heavier bullet with a larger mass has more kinetic pulse or punch. The lighter bullet of less mass will disrupt less. Both can release the same kinetic energy but the heavier bullet will move a greater target mass at a lesser velocity than a lighter bullet at a greater velocity. Now I havnt studied kinetic pulse enough but with slingshots the ammo shoots at a much slower velocity than rifles so kinetic pulse isn't much of a factor, or is it? When in doubt do the soup can test(the slingshot ballistic test)

 

This is where the kinetic pulse punch in. It shows that a slow vel projectile with great mass may have a relatively bigger momentum but lower energy whereas a fast moving light ammo may have less momentum but higher energy. The productb of energy and momentum gives an indication of the kinetic pulse of the projectile.

If we look only at energy this can be fooling us for big ammo with slow vel!

 

Yup, that's what dogbox and wll were explaining earlier :thumbsup:

 

Take a bowling ball going 100fps and a 124gr ball going 1200fps (NATO 9mm) One will put a hole through part of you and could kill you, the other will knock you through the living room wall .... it may not penetrate you but do some serious crushing damage.

Slingshots shoot mini bowling balls as they can't (as of yet, realistically) reach those higher velocities.

wll

 

I have been shooting animals with slingshots for the better part of 40 years, heavy works and light sucks. These types of debates are next to worthless when it comes to slingshots.

 

One might also get a trauma when he listens to James Blunt for too long...so....just sayin´...

 

Who's James Blunt? Is that the guy who lost love is Simona?